Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into core/efi

Pull v4.4 EFI updates from Matt Fleming:

  - Make the EFI System Resource Table (ESRT) driver explicitly
    non-modular by ripping out the module_* code since Kconfig doesn't
    allow it to be built as a module anyway. (Paul Gortmaker)

  - Make the x86 efi=debug kernel parameter, which enables EFI debug
    code and output, generic and usable by arm64. (Leif Lindholm)

  - Add support to the x86 EFI boot stub for 64-bit Graphics Output
    Protocol frame buffer addresses. (Matt Fleming)

  - Detect when the UEFI v2.5 EFI_PROPERTIES_TABLE feature is enabled
    in the firmware and set an efi.flags bit so the kernel knows when
    it can apply more strict runtime mapping attributes - Ard Biesheuvel

  - Auto-load the efi-pstore module on EFI systems, just like we
    currently do for the efivars module. (Ben Hutchings)

  - Add "efi_fake_mem" kernel parameter which allows the system's EFI
    memory map to be updated with additional attributes for specific
    memory ranges. This is useful for testing the kernel code that handles
    the EFI_MEMORY_MORE_RELIABLE memmap bit even if your firmware
    doesn't include support. (Taku Izumi)

Note: there is a semantic conflict between the following two commits:

  8a53554e12e9 ("x86/efi: Fix multiple GOP device support")
  ae2ee627dc87 ("efifb: Add support for 64-bit frame buffer addresses")

I fixed up the interaction in the merge commit, changing the type of
current_fb_base from u32 to u64.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 23 insertions, 1 deletions

diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c
index 4bfff349b1fb..95d293b7445a 100644
--- a/drivers/video/fbdev/efifb.c
+++ b/drivers/video/fbdev/efifb.c
@@ -114,6 +114,20 @@ static int efifb_setup(char *options)
 	return 0;
 }
 
+static inline bool fb_base_is_valid(void)
+{
+	if (screen_info.lfb_base)
+		return true;
+
+	if (!(screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE))
+		return false;
+
+	if (screen_info.ext_lfb_base)
+		return true;
+
+	return false;
+}
+
 static int efifb_probe(struct platform_device *dev)
 {
 	struct fb_info *info;
@@ -141,7 +155,7 @@ static int efifb_probe(struct platform_device *dev)
 		screen_info.lfb_depth = 32;
 	if (!screen_info.pages)
 		screen_info.pages = 1;
-	if (!screen_info.lfb_base) {
+	if (!fb_base_is_valid()) {
 		printk(KERN_DEBUG "efifb: invalid framebuffer address\n");
 		return -ENODEV;
 	}
@@ -160,6 +174,14 @@ static int efifb_probe(struct platform_device *dev)
 	}
 
 	efifb_fix.smem_start = screen_info.lfb_base;
+
+	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) {
+		u64 ext_lfb_base;
+
+		ext_lfb_base = (u64)(unsigned long)screen_info.ext_lfb_base << 32;
+		efifb_fix.smem_start |= ext_lfb_base;
+	}
+
 	efifb_defined.bits_per_pixel = screen_info.lfb_depth;
 	efifb_defined.xres = screen_info.lfb_width;
 	efifb_defined.yres = screen_info.lfb_height;